CN113223450B - Backlight module based on micro light-emitting diode unit and display panel - Google Patents
Backlight module based on micro light-emitting diode unit and display panel Download PDFInfo
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- CN113223450B CN113223450B CN202110529695.2A CN202110529695A CN113223450B CN 113223450 B CN113223450 B CN 113223450B CN 202110529695 A CN202110529695 A CN 202110529695A CN 113223450 B CN113223450 B CN 113223450B
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
- G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
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Abstract
The embodiment of the application provides a backlight module based on a micro light-emitting diode unit and a display panel. In the backlight module based on the micro light-emitting diode unit provided by the embodiment of the application, because the feedback compensation unit electrically connected with the micro light-emitting diode unit and the control unit is arranged, the feedback compensation unit converts the detected cross voltage of the micro light-emitting diode unit into the compensation voltage and outputs the compensation voltage to the control unit, the control unit outputs the compensated driving signal according to the compensation voltage, and the driving unit outputs the compensated driving current according to the compensated driving signal, so that the working voltage of the micro light-emitting diode unit driven by the compensated driving current is in the rated voltage range, the working current of the micro light-emitting diode unit is also in the rated current range, the probability of the micro light-emitting diode unit that the current obviously fluctuates can be reduced, and the probability of the micro light-emitting diode unit that the current flickers can be reduced.
Description
Technical Field
The application relates to the technical field of display, in particular to a backlight module based on a miniature light emitting diode unit and a display panel.
Background
Micro light emitting diode (μ LED, including Mini LED and Micro LED) display panels are a new generation of display technology, and have the advantages of higher brightness, better light emitting efficiency and lower power consumption compared to the existing display panels.
At present, in the working process of a micro light emitting diode display panel, due to the influences of unstable power supply, parasitic capacitance discharge in a field effect transistor inside the display panel and the like, the current passing through the micro light emitting diode in a backlight module changes, so that the current passing through the micro light emitting diode generates obvious fluctuation, the micro light emitting diode flickers, and the display effect of the micro light emitting diode display panel is further influenced.
Disclosure of Invention
The application provides a backlight module based on a miniature light-emitting diode unit and a display panel aiming at the defects of the prior art, and aims to solve the technical problem that in the prior art, the current passing through the miniature light-emitting diode in the backlight module in the working process of the miniature light-emitting diode display panel obviously fluctuates to cause the miniature light-emitting diode to flicker.
In a first aspect, an embodiment of the present application provides a backlight module based on a micro light emitting diode unit, including:
a micro light emitting diode unit;
the driving unit is electrically connected with the micro light-emitting diode unit;
the control unit is electrically connected with the driving unit;
the feedback compensation unit is electrically connected with the micro light-emitting diode unit and the control unit and is used for detecting the cross voltage of the micro light-emitting diode unit, converting the cross voltage into a compensation voltage and outputting the compensation voltage; the control unit is used for outputting a compensated driving signal according to the compensation voltage, and the driving unit is used for outputting a compensated driving current according to the compensated driving signal, so that the working voltage of the micro light-emitting diode unit under the drive of the compensated driving current is in a rated voltage range.
In a second aspect, an embodiment of the present application provides a display panel, including: the backlight module based on the micro light emitting diode unit provided by the first aspect is provided.
The beneficial technical effects brought by the technical scheme provided by the embodiment of the application comprise:
in the backlight module based on the micro light-emitting diode unit provided by the embodiment of the application, because the feedback compensation unit electrically connected with the micro light-emitting diode unit and the control unit is arranged, the feedback compensation unit converts the detected cross voltage of the micro light-emitting diode unit into the compensation voltage and outputs the compensation voltage to the control unit, the control unit outputs the compensated driving signal according to the compensation voltage, and the driving unit outputs the compensated driving current according to the compensated driving signal, so that the working voltage of the micro light-emitting diode unit driven by the compensated driving current is in the rated voltage range, the working current of the micro light-emitting diode unit is also in the rated current range, the probability of the micro light-emitting diode unit that the current obviously fluctuates can be reduced, and the probability of the micro light-emitting diode unit that the current flickers can be reduced.
Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.
Drawings
The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a schematic view of a frame structure of a backlight module based on a micro light emitting diode unit according to an embodiment of the present disclosure;
fig. 2 is a schematic diagram of a frame structure of a feedback compensation unit in a backlight module based on a micro light emitting diode unit according to an embodiment of the present disclosure;
fig. 3 is a schematic circuit structure diagram of a backlight module based on a micro light emitting diode unit according to an embodiment of the present disclosure.
Description of reference numerals:
10-a micro light emitting diode unit;
20-a drive unit;
30-a control unit; 31-control group subunit; 311-a first switch; 312-a control module;
40-a feedback compensation unit; 41-a voltage detection unit; 42-a compensation voltage generation unit; 421-operational amplifier subunit; 4211-a first interface; 4212-a second interface; 4213-third interface; 4214-fourth interface; 4215-fifth interface; 422-impedance subunit; 4221-a first resistor subunit; 4222-a second resistor subunit; 4223-a third resistor subunit;
101-a first node; 102-a second node; 103-third node.
Detailed Description
Reference will now be made in detail to the present application, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar parts or parts having the same or similar functions throughout. In addition, if a detailed description of the known art is unnecessary for the features of the present application shown, it is omitted. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.
It will be understood by those within the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.
The inventor of the present application has studied and found that, in the working process of the micro light emitting diode display panel, due to the influences of unstable power supply, discharge of parasitic capacitance in a field effect transistor inside the display panel, and the like, the current passing through the micro light emitting diode in the backlight module changes, and the current passing through the micro light emitting diode generates obvious fluctuation, so that the micro light emitting diode flickers, and the display effect of the micro light emitting diode display panel is further influenced.
Moreover, when the current passing through the micro light-emitting diode is lower than the current threshold of the control module for controlling the micro light-emitting diode, the control module can judge that the circuit where the micro light-emitting diode is located is open, so that the micro light-emitting diode is turned off, the micro light-emitting diode cannot normally emit light, and the display effect of the micro light-emitting diode display panel is further influenced.
The application provides a backlight unit and display panel based on miniature emitting diode unit aims at solving prior art technical problem as above.
The following describes the technical solutions of the present application and how to solve the above technical problems with specific embodiments.
The embodiment of the present application provides a backlight module based on a micro light emitting diode unit, and a schematic structural diagram of the backlight module based on the micro light emitting diode unit is shown in fig. 1, and the backlight module includes:
a micro light emitting diode unit 10;
a driving unit 20 electrically connected to the micro light emitting diode unit 10;
a control unit 30 electrically connected to the driving unit 20;
the feedback compensation unit 40 is electrically connected with the micro light-emitting diode unit 10 and the control unit 30, and is used for detecting the cross voltage of the micro light-emitting diode unit 10, converting the cross voltage into a compensation voltage and outputting the compensation voltage; the control unit 30 is configured to output a compensated driving signal according to the compensation voltage, and the driving unit 20 is configured to output a compensated driving current according to the compensated driving signal, so that the operating voltage of the micro light emitting diode unit 10 driven by the compensated driving current is within a rated voltage range.
In the backlight module based on the micro light emitting diode unit provided in the embodiment of the present application, because the feedback compensation unit 40 electrically connected to the micro light emitting diode unit 10 and the control unit 30 is provided, the feedback compensation unit 40 converts the detected cross voltage of the micro light emitting diode unit 10 into a compensation voltage and outputs the compensation voltage to the control unit 30, the control unit 30 outputs a compensated driving signal according to the compensation voltage, and the driving unit 20 outputs a compensated driving current according to the compensated driving signal, so that the working voltage of the micro light emitting diode unit 10 driven by the compensated driving current is in a rated voltage range, and thus the working current of the micro light emitting diode unit 10 is also in the rated current range, and the probability of the micro light emitting diode unit 10 that the current obviously fluctuates can be reduced, and thus the probability of the micro light emitting diode unit 10 that the flicker occurs can be reduced.
In the embodiment of the present application, the micro light emitting diode unit 10, the driving unit 20 and the control unit 30 are electrically connected in sequence, and both the micro light emitting diode unit 10 and the control unit 30 are electrically connected to the feedback compensation unit 40. The feedback compensation unit 40 is configured to detect a voltage across the micro light emitting diode unit 10, convert the voltage across the micro light emitting diode unit into a compensation voltage, and output the compensation voltage to the control unit 30, the control unit 30 is configured to output a compensated driving signal according to the compensation voltage, and output the driving signal to the driving unit 20, and the driving unit 20 is configured to output a compensated driving current according to the compensated driving signal, so that a working voltage of the micro light emitting diode unit 10 driven by the compensated driving current is within a rated voltage range.
In the embodiment of the present application, by setting the feedback compensation unit 40, the working current of the micro light emitting diode unit 10 can be in the rated current range, the probability of the current fluctuation phenomenon occurring in the micro light emitting diode unit 10 can be reduced, the probability of the flicker occurring in the micro light emitting diode unit 10 can be reduced, and the display effect of the display panel to which the backlight module provided in the embodiment of the present application is applied can be ensured.
Moreover, according to the backlight module provided by the embodiment of the application, by making the working current of the micro light emitting diode unit 10 be within the rated current range, the situation that the working current of the micro light emitting diode unit 10 is lower than the current threshold of the control unit 30 can be avoided, so that the open circuit fault detection function in the control unit 30 can be ensured to normally operate, the normal operation of the micro light emitting diode unit 10 can be ensured, and the display effect of the display panel to which the backlight module provided by the embodiment of the application is applied is further ensured. It should be noted that the current threshold of the control unit 30 refers to that when the operating current of the micro light emitting diode unit 10 is smaller than the current threshold, the open-circuit fault detection module of the control unit 30 determines that the circuit where the micro light emitting diode unit 10 is located is open at this time, so that the micro light emitting diode unit 10 is turned off.
In the embodiment of the present application, the Micro LED unit 10 includes at least one or a combination of a Mini LED (Light-Emitting Diode) and a Micro LED.
In one embodiment of the present application, the compensation voltage is inversely related to the cross-voltage. In the embodiment of the present application, the voltage across the micro light emitting diode unit 10 means that a voltage difference between two ends of the micro light emitting diode unit 10 is a working voltage of the micro light emitting diode unit 10. The feedback compensation unit 40 converts the voltage across the micro led unit 10 into a compensation voltage, and outputs the compensation voltage to the control unit 30; the control unit 30 outputs the compensated driving signal according to the compensation voltage, and the driving unit 20 outputs the compensated driving current according to the compensated driving signal, so that the operating voltage of the micro light emitting diode unit 10 driven by the compensated driving current is within the rated voltage range.
In the embodiment of the present application, when the feedback compensation unit 40 detects that the voltage across the micro light emitting diode unit 10 is smaller than the rated voltage range, the feedback compensation unit 40 calculates the compensation voltage required by the micro light emitting diode unit 10 according to the detected voltage across the micro light emitting diode unit and the preset rated voltage of the micro light emitting diode unit 10, so that the working voltage of the micro light emitting diode unit 10 is within the rated voltage range after the control unit 30 and the driving unit 20 act on the compensation voltage. Therefore, the feedback compensation unit 40 calculates the compensation voltage required by the micro light emitting diode unit 10 to be larger as the voltage across the micro light emitting diode unit 10 is smaller, so that the operating voltage of the micro light emitting diode unit 10 is in the rated voltage range.
The detailed analysis process of the negative correlation between the compensation voltage and the cross voltage will be described in detail later, and will not be described herein again.
In one embodiment of the present application, as shown in fig. 2, the feedback compensation unit 40 includes a voltage detection unit 41 and a compensation voltage generation unit 42 that are electrically connected. The voltage detection unit 41 is electrically connected to both ends of the micro light emitting diode unit 10, and is configured to transmit the detected voltage across the micro light emitting diode unit 10 to the compensation voltage generation unit 42; the compensation voltage generating unit 42 is configured to generate a compensation voltage according to the voltage across the capacitor, and transmit the compensation voltage to the control unit 30.
In the embodiment of the present application, the voltage detection unit 41 is configured to detect the voltage across the micro led unit 10, one end of the voltage detection unit 41 is electrically connected to one end of the compensation voltage generation unit 42, and both ends of the voltage detection unit 41 and the micro led unit 10 are electrically connected, so that the voltage detection unit 41 can transmit the detected voltage across to the compensation voltage generation unit 42.
The compensation voltage generating unit 42 is configured to generate a compensation voltage according to the cross voltage, and specifically, the compensation voltage generating unit 42 calculates the compensation voltage required by the micro light emitting diode unit 10 according to the detected cross voltage and a preset rated voltage of the micro light emitting diode unit 10; the other end of the compensation voltage generating unit 42 is electrically connected to the control unit 30, thereby transmitting the generated compensation voltage to the control unit 30. Then, the control unit 30 outputs the compensated driving signal according to the compensation voltage, and the driving unit 20 outputs the compensated driving current according to the compensated driving signal, so that the working voltage of the micro light emitting diode unit 10 driven by the compensated driving current is within the rated voltage range. Therefore, the probability of the current of the micro light-emitting diode unit 10 obviously fluctuating can be reduced, the probability of the micro light-emitting diode unit 10 flickering can be reduced, and the display effect of the display panel with the backlight module provided by the embodiment of the application can be guaranteed.
In one embodiment of the present application, as shown in fig. 2, the compensation voltage generating unit 42 includes an operational amplifying sub-unit 421 and an impedance sub-unit 422; one end of the impedance subunit 422 is electrically connected to the operational amplifier subunit 421, and the other end of the impedance subunit 422 is electrically connected to the voltage detection unit 41, and is configured to receive the voltage across the micro light emitting diode unit 10 detected by the voltage detection unit 41.
In the embodiment of the present application, as shown in fig. 3, a first input terminal, a second input terminal, and an output terminal of the operational amplifier subunit 421 are electrically connected to the first node 101, the voltage terminal, and the second node 102, respectively. A first input terminal of the operational amplifier subunit 421 is electrically connected to the first node 101, a second input terminal of the operational amplifier subunit 421 is electrically connected to a voltage terminal, and optionally, an output voltage of the voltage terminal is V DAC The output terminal of the operational amplifier subunit 421 is electrically connected to the second node 102. The control unit 30 is electrically connected to the second node 102; the first input terminal of the operational amplifier subunit 421 is short-circuited with the output terminal of the operational amplifier subunit 421, so that the operational amplifier subunit 421 forms a closed-loop operational amplifier structure.
It should be noted that, as shown in fig. 3, in the schematic circuit structure diagram of the backlight module based on the micro light emitting diode unit provided in the embodiment of the present application, the operational amplifier sub-unit 421 further includes a first interface 4211, a second interface 4212, a third interface 4213, a fourth interface 4214, and a fifth interface 4215. Optionally, in this embodiment of the application, the first interface 4211 is a VIN interface, and is used for connecting a power supply; the second interface 4212 is an EN interface; the third interface 4213 is a GND interface and is used for grounding; the fourth interface 4214 is an FQBQ interface, and the fifth interface 4215 is an SW interface and is electrically connected to the second node 102. In the embodiment of the present application, a first input terminal of the operational amplifier subunit 421 is electrically connected to the first node 101 through the FB interface.
In the embodiment of the present application, the first terminal, the second terminal, the third terminal, and the fourth terminal of the impedance subunit 422 are electrically connected to the first node 101, the voltage detection unit 41, the second node 102, and the ground terminal, respectively. As shown in fig. 3, the first terminal of the impedance subunit 422 is electrically connected to the first node 101, and since the first terminal of the impedance subunit 422 and the first input terminal of the operational amplifier subunit 421 are both directly electrically connected to the first node 101, the potential of the first terminal of the impedance subunit 422 is equal to the potential of the first input terminal of the operational amplifier subunit 421.
A second terminal of the impedance subunit 422 is electrically connected to the voltage detection unit 41, so that the voltage detection unit 41 transmits the detected cross voltage of the micro light emitting diode unit 10 to the impedance subunit 422.
The third terminal of the impedance subunit 422 is electrically connected to the second node 102, and since the third terminal of the impedance subunit 422, the output terminal of the operational amplifier subunit 421 and the input terminal of the control unit 30 are all directly electrically connected to the second node 102, the potential of the third terminal of the impedance subunit 422, the potential of the output terminal of the operational amplifier subunit 421 and the potential of the input terminal of the control unit 30 are equal. The fourth terminal of the impedance subunit 422 is electrically connected to the ground terminal.
In one embodiment of the present application, as shown in fig. 3, the impedance subunit 422 includes a first resistance subunit 4221, a second resistance subunit 4222, and a third resistance subunit 4223.
A first end of the first resistor subunit 4221, a first end of the second resistor subunit 4222 and a first end of the third resistor subunit 4223 are commonly used as a first end of the impedance subunit 422 and are electrically connected to the first node 101; the second terminal of the first resistor subunit 4221 serves as the third terminal of the impedance subunit 422, and is electrically connected to the second node 102; a second end of the third resistor subunit 4223 serves as a second end of the impedance subunit 422, and is electrically connected to the voltage detection unit 41; the voltage across the micro led unit 10 detected by the voltage detecting unit 41 is sequentially transmitted to the first input terminal of the operational amplifier subunit 421 through the third resistor subunit 4223 and the first node 101.
In the embodiments of the present application, in order to facilitate understanding of the inventive concept of the present application, a description will be given with reference to a circuit configuration shown in fig. 3. For convenience of description, the resistance values of the first, second and third resistor subunits 4221, 4222 and 4223 are respectively represented by R 1 、R 2 And R 3 It is shown that, at the same time, a third node 103 is marked in the connection circuit between the voltage detection unit 41 and the impedance subunit 422.
According to the above analysis, the operational amplifier subunit 421 forms a closed-loop operational amplifier structure, and according to the principle of virtual short and virtual far, the potentials of the first input terminal of the operational amplifier subunit 421 and the second input terminal of the operational amplifier subunit 421 are equal. As shown in fig. 3, the voltage terminal electrically connected to the second input terminal of the operational amplifier subunit 421 specifically includes a positive electrode of a voltage source, a negative electrode of the voltage source may be grounded, and a voltage of the positive electrode of the voltage source is V DAC Then the voltage at the first input terminal of the operational amplifier subunit 421 is also equal to V DAC Since the potential of the first input terminal of the operational amplifier subunit 421, the potential of the first terminal of the impedance subunit 422 and the potential of the first node 101 are equal, V is used for convenience of description DAC Indicating the potential difference of the first node 101.
From the above analysis, the potential of the third terminal of the impedance subunit 422, the potential of the output terminal of the operational amplifier subunit 421 and the potential of the input terminal of the control unit 30 are equal, and for convenience of description, V is used in the following out Indicating the potential difference at three points. Since the second terminal of the impedance subunit 422 is directly and electrically connected to the voltage detection unit 41, the potential of the second terminal of the impedance subunit 422, the potential of the output terminal of the voltage detection unit 41, and the potential of the third node 103 are the same, and since the output terminal of the voltage detection unit 41 is the detected voltage across the micro light emitting diode unit 10, V is used for convenience of description LED Representing the difference in potential at three, i.e. V LED Representing the voltage values at the three.
According to the virtual short and virtual break principle of the operational amplifier, when the operational amplifier unit 421 is in the virtual break state, the current I from the first node 101 to the first input terminal of the operational amplifier unit 421 4 Equal to zero. According to the voltage value V of the third node 103 LED And the voltage value V of the first node 101 DAC There are two cases of the magnitude relationship of (a) and (b), and a specific analysis is made below for the two cases.
In the first case:
when the voltage value V of the third node 103 is LED Is smaller than the voltage value V of the first node 101 DAC Then, according to kirchhoff's law, the current I flowing through the first resistor subunit 4221 is known 1 Is equal to the current I flowing through the second resistor subunit 4222 2 And a current I flowing through the third resistor subunit 4223 3 The sum is shown in the expression (1).
According to kirchhoff's law, the voltage I of the first resistor subunit 4221 is known 1 *R 1 The specific calculation method of (2) is shown in the expression.
I 1 *R 1 ＝V out -V DAC Expression (2)
The following expression (3) can be obtained from the expressions (1) and (2).
From the expression (3), the resistance value R of the first resistor subunit 4221 can be found 1 Resistance value R of second resistor subunit 4222 2 Resistance value R of third resistor subunit 4223 3 And the output voltage V of the voltage terminal DAC In the determined case, the voltage value V of the second node 102 out The voltage V across the micro-LED unit 10 output from the output terminal of the voltage detection unit 41 LED Is increased and decreased, i.e. the compensation voltage outputted by the feedback compensation unit 40 and the voltage across the micro-led unit 10V are decreased LED A negative correlation.
In the second case:
when the voltage value V of the third node 103 LED Greater than the voltage value V of the first node 101 DAC Then, according to kirchhoff's law, the current I flowing through the first resistor subunit 4221 is known 1 Equal to the current I flowing through the second resistor subunit 4222 2 And a current I flowing through the third resistor subunit 4223 3 The sum is shown in the expression (1).
The following expression (5) can be obtained from the expression (4) and the expression (2).
From the expression (5), the resistance value R of the first resistor subunit 4221 1 Resistance value R of second resistor subunit 4222 2 Resistance value R of third resistor subunit 4223 3 And the output voltage V of the voltage terminal DAC In the determined case, the voltage value V of the second node 102 out The voltage V across the micro-LED unit 10 outputted from the output terminal of the voltage detection unit 41 LED Is increased and decreased, i.e. the compensation voltage outputted by the feedback compensation unit 40 and the voltage across the micro-led unit 10V are decreased LED A negative correlation.
In one embodiment of the present application, the resistance relationship among the first resistor subunit 4221, the second resistor subunit 4222 and the third resistor subunit 4223 is determined when the operating voltage of the micro light emitting diode unit 10 is in the rated voltage range.
In the embodiment of the present application, the voltage V across the micro light emitting diode unit 10 LED At the rated voltage, the voltage V of the second node 102 out Equal to zero, the resistance value R of the first resistor subunit 4221 can be determined according to the above expression (3) and expression (5) 1 Resistance value R of second resistor subunit 4222 2 Resistance value R of third resistor subunit 4223 3 The relationship between them.
It should be noted that in the embodiment of the present application, as shown in fig. 3, the first resistor subunit 4221, the second resistor subunit 4222, and the third resistor subunit 4223 may all be a single resistor structure, or may include a plurality of resistor structures, and the plurality of resistor structures may be connected in series, in parallel, or the like, and it is only necessary to ensure that the connection relationship and the resistance relationship of the first resistor subunit 4221, the second resistor subunit 4222, and the third resistor subunit 4223 meet the requirements of the present application.
In one embodiment of the present application, the control unit 30 comprises at least one control group subunit 31; the control group subunit 31 includes a first switch 311 and a control module 312 electrically connected; the output end of the control module 312 is electrically connected to the control end of at least one driving unit 20, and the first end of the driving unit 20 is electrically connected to at least one micro light emitting diode unit 10.
In the embodiment of the present application, the control unit 30 includes at least one control Group subunit 31, and optionally, as shown in fig. 3, the control unit 30 includes nine control Group subunits 31, where the nine control Group subunits 31 are denoted by Group1 to Group9 in fig. 3. Each control group subunit 31 includes a first switch 311 and a control module 312, one end of the first switch 311 is electrically connected to the second node 102 for receiving the compensation voltage sent by the feedback compensation unit 40, and the other end of the first switch 311 is electrically connected to an input end of the control module 312; the output end of the control module 312 is electrically connected to the control end of at least one driving unit 20, and is configured to convert the received compensation voltage into a compensated driving signal and output the compensated driving signal to the control end of the driving unit 20. As can be seen from fig. 3, the control terminal of the driving unit 20 is the gate of the fet, and the first terminal of the driving unit 20 is the drain of the fet.
Because the first end of the driving unit 20 is electrically connected to at least one micro light emitting diode unit 10, under the control of the compensated driving signal, the driving unit 20 generates the compensated driving current according to the compensated driving signal, so that the working voltage of the micro light emitting diode unit 10 driven by the compensated driving current is in the rated voltage range, the probability of the micro light emitting diode unit 10 that the current obviously fluctuates can be reduced, and the probability of the micro light emitting diode unit 10 that the micro light emitting diode unit 10 flickers can be reduced.
In the embodiment of the present application, each control group subunit 31 can be connected in parallel to the control terminals of eight driving units 20, and the first terminal of each driving unit 20 is connected to one micro led unit 10; alternatively, each control group subunit 31 may be electrically connected to the control terminal of one driving unit 20, and the first terminal of each driving unit 20 is connected in parallel to eight micro light emitting diode units 10. Therefore, under the condition that the current of one driving unit 20 is too small due to rise time and the power supply is unstable, the feedback compensation unit 40 can make the working voltage of all the micro light-emitting diode units 10 in one control group subunit 31 within the rated voltage range at one time, so that the current stabilization efficiency of the backlight module can be improved, the probability of the micro light-emitting diode units 10 that the current obviously fluctuates can be further reduced, the probability of the micro light-emitting diode units 10 that the flicker occurs can be further reduced, and the display effect of the display panel to which the backlight module provided by the embodiment of the application is applied can be further ensured.
It should be noted that, in order to facilitate the reader to intuitively understand the circuit structure shown in fig. 3, the control module 312 in the remaining control group subunit 31, the driving unit 20 electrically connected to the control module 312, and the micro led unit 10 electrically connected to the driving unit 20 are indicated by ellipses in fig. 3.
In one embodiment of the present application, at least one micro light emitting diode unit 10 electrically connected to the same control module 312 is electrically connected to the voltage detection unit 41 of one feedback compensation unit 40.
In one embodiment of the present application, one end of the first switch 311 is electrically connected to the feedback compensation unit 40, and the other end is connected to an input end of the control module 312; the first switch is used for controlling the connection or disconnection between the control module 312 and the feedback compensation unit 40, and when the control module 312 is connected to the feedback compensation unit 40, the operating voltage of each micro light emitting diode unit 10 electrically connected to the same control module 312 is within the rated voltage range.
In the embodiment of the present application, since the micro led units 10 are connected in parallel, only one of all the micro led units 10 electrically connected to the control module 312 of each control group subunit 31 needs to be electrically connected to the voltage detection unit 41 of one feedback compensation unit 40, and one voltage detection unit 41 can simultaneously detect the cross voltage of all the micro led units 10 electrically connected to the same control group subunit 31.
Based on the same inventive concept, an embodiment of the present application provides a display panel, including: the backlight module based on the micro light-emitting diode unit provided by the above embodiments.
The display panel provided by the embodiment of the present application has the same inventive concept and the same advantageous effects as the embodiments of the previous embodiments, and the content of the backlight module based on the micro light emitting diode unit in the display panel, which is not shown in detail in the previous embodiments, can refer to the embodiments of the previous embodiments, and is not described herein again.
By applying the embodiment of the application, the following beneficial effects can be at least realized:
in the backlight module based on the micro light emitting diode unit provided in the embodiment of the present application, because the feedback compensation unit 40 electrically connected to the micro light emitting diode unit 10 and the control unit 30 is provided, the feedback compensation unit 40 converts the detected cross voltage of the micro light emitting diode unit 10 into a compensation voltage and outputs the compensation voltage to the control unit 30, the control unit 30 outputs a compensated driving signal according to the compensation voltage, and the driving unit 20 outputs a compensated driving current according to the compensated driving signal, so that the working voltage of the micro light emitting diode unit 10 driven by the compensated driving current is in a rated voltage range, and thus the working current of the micro light emitting diode unit 10 is also in the rated current range, and the probability of the micro light emitting diode unit 10 that the current obviously fluctuates can be reduced, and thus the probability of the micro light emitting diode unit 10 that the flicker occurs can be reduced.
Moreover, according to the backlight module provided by the embodiment of the application, by making the working current of the micro light emitting diode unit 10 be within the rated current range, the situation that the working current of the micro light emitting diode unit 10 is lower than the current threshold of the control unit 30 can be avoided, so that the open circuit fault detection function in the control unit 30 can be ensured to normally operate, the normal operation of the micro light emitting diode unit 10 can be ensured, and the display effect of the display panel to which the backlight module provided by the embodiment of the application is applied is further ensured.
Those of skill in the art will appreciate that the various operations, methods, steps in the processes, acts, or solutions discussed in this application can be interchanged, modified, combined, or eliminated. Further, other steps, measures, or schemes in various operations, methods, or flows that have been discussed in this application can be alternated, altered, rearranged, broken down, combined, or deleted. Further, steps, measures, schemes in the prior art having various operations, methods, procedures disclosed in the present application may also be alternated, modified, rearranged, decomposed, combined, or deleted.
The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.
The foregoing is only a few embodiments of the present application and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present application, and that these improvements and modifications should also be considered as the protection scope of the present application.
Claims (9)
1. The utility model provides a backlight unit based on miniature emitting diode unit which characterized in that includes:
a micro light emitting diode unit;
the driving unit is electrically connected with the micro light-emitting diode unit;
the control unit is electrically connected with the driving unit;
the feedback compensation unit is electrically connected with the miniature light-emitting diode unit and the control unit and is used for detecting the cross voltage of the miniature light-emitting diode unit, converting the cross voltage into a compensation voltage and outputting the compensation voltage; the control unit is used for outputting a compensated driving signal according to the compensation voltage, and the driving unit is used for outputting a compensated driving current according to the compensated driving signal, so that the working voltage of the micro light-emitting diode unit under the drive of the compensated driving current is in a rated voltage range; the feedback compensation unit comprises a voltage detection unit and a compensation voltage generation unit which are electrically connected; the voltage detection unit is electrically connected with both ends of the micro light-emitting diode unit and is used for transmitting the detected cross voltage to the compensation voltage generation unit; the compensation voltage generating unit is used for generating the compensation voltage according to the cross voltage and transmitting the compensation voltage to the control unit; the compensation voltage generation unit comprises an operational amplification subunit and an impedance subunit; the first input end, the second input end and the output end of the operational amplifier subunit are respectively and electrically connected with the first node, the voltage terminal and the second node; the control unit is electrically connected with the second node; and the first input end of the operational amplification subunit is in short circuit with the output end of the operational amplification subunit.
2. A backlight module according to claim 1, wherein the compensation voltage is inversely related to the cross-voltage.
3. The backlight module as claimed in claim 1, wherein the first terminal, the second terminal, the third terminal and the fourth terminal of the impedance subunit are electrically connected to the first node, the voltage detection unit, the second node and a ground terminal, respectively.
4. The backlight module as claimed in claim 3, wherein the impedance subunit comprises a first resistor subunit, a second resistor subunit and a third resistor subunit;
the first end of the first resistance subunit, the first end of the second resistance subunit and the first end of the third resistance subunit are used as the first end of the impedance subunit and are electrically connected with the first node;
the second end of the first resistor subunit is used as the third end of the impedance subunit and is electrically connected with the second node;
the second end of the third resistance subunit is used as the second end of the impedance subunit and is electrically connected with the voltage detection unit; and the cross voltage of the micro light-emitting diode unit is transmitted to the first input end of the operational amplification subunit through the third resistor subunit and the first node in sequence.
5. The backlight module according to claim 4, wherein the resistance relationship among the first resistor subunit, the second resistor subunit and the third resistor subunit is determined when the operating voltage of the micro light emitting diode unit is within a rated voltage range.
6. The backlight module as claimed in claim 1, wherein the control unit comprises at least one control group sub-unit;
the control group subunit comprises a first switch and a control module which are electrically connected; the output end of the control module is electrically connected with the control end of at least one driving unit, and the first end of the driving unit is electrically connected with at least one micro light-emitting diode unit.
7. The backlight module as claimed in claim 6, wherein at least one of the micro LED units electrically connected to the same control module is electrically connected to a voltage detecting unit of the feedback compensation unit.
8. The backlight module according to claim 6, wherein one end of the first switch is electrically connected to the feedback compensation unit, and the other end of the first switch is connected to the input end of the control module;
the first switch is used for controlling the connection or disconnection between the control module and the feedback compensation unit, and under the condition that the control module is connected with the feedback compensation unit, the working voltage of each micro light-emitting diode unit electrically connected to the same control module is within a rated voltage range.
9. A display panel, comprising: backlight module according to any of claims 1 to 8 based on a micro light emitting diode unit.
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| CN202110529695.2A CN113223450B (en) | 2021-05-14 | 2021-05-14 | Backlight module based on micro light-emitting diode unit and display panel |
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| CN202110529695.2A CN113223450B (en) | 2021-05-14 | 2021-05-14 | Backlight module based on micro light-emitting diode unit and display panel |
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| KR102459703B1 (en) * | 2014-12-29 | 2022-10-27 | 엘지디스플레이 주식회사 | Organic light emitting diode display and drving method thereof |
| CN107039004B (en) * | 2017-06-08 | 2019-04-30 | 深圳市华星光电半导体显示技术有限公司 | The aging compensation approach of AMOLED display panel |
| CN107146576B (en) * | 2017-07-06 | 2018-11-30 | 深圳市华星光电技术有限公司 | A method of for driving pixel circuit |
| CN110634432B (en) * | 2019-10-25 | 2023-05-12 | 京东方科技集团股份有限公司 | OLED pixel circuit, driving method, aging detection method and display panel |
| CN112767886A (en) * | 2021-01-18 | 2021-05-07 | 惠科股份有限公司 | Backlight adjusting system, adjusting method thereof and display device |
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